From: Jonathan Wakely <jwakely@redhat.com>
To: libstdc++@gcc.gnu.org, gcc-patches@gcc.gnu.org
Subject: [committed] libstdc++: Support VAX floats in std::strong_order
Date: Thu, 10 Mar 2022 11:51:16 +0000 [thread overview]
Message-ID: <20220310115116.1716777-1-jwakely@redhat.com> (raw)
Tested x86_64-linux, and basic soundness check on vax-dec-netbsdelf.
Pushed to trunk.
-- >8 --
The VAX float and double format does not support NaN, so the
std::partial_ordering returned by <=> will never be 'unordered'. We can
just use the partial_ordering value as the strong_ordering.
libstdc++-v3/ChangeLog:
* libsupc++/compare (_Strong_ordering::_S_fp_cmp) [__vax__]: Use
<=> comparison.
---
libstdc++-v3/libsupc++/compare | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/libstdc++-v3/libsupc++/compare b/libstdc++-v3/libsupc++/compare
index 050cf7ed20d..3c22d9addf1 100644
--- a/libstdc++-v3/libsupc++/compare
+++ b/libstdc++-v3/libsupc++/compare
@@ -843,6 +843,11 @@ namespace std
static constexpr strong_ordering
_S_fp_cmp(_Tp __x, _Tp __y) noexcept
{
+#ifdef __vax__
+ // VAX format has no NaN, only "excess" for Inf, so totally ordered.
+ return __builtin_bit_cast(strong_ordering, __x <=> __y);
+#endif
+
auto __ix = _S_fp_bits(__x);
auto __iy = _S_fp_bits(__y);
--
2.34.1
next reply other threads:[~2022-03-10 11:51 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-10 11:51 Jonathan Wakely [this message]
2022-03-10 12:16 ` Jonathan Wakely
2022-03-10 14:27 ` Jonathan Wakely
2022-03-10 17:46 ` Koning, Paul
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